Glow bottles serve as starters in ballast circuits for conventional fluorescent lamps. Initially, a glow bottle is in a low impedance state, causing current to build up in a ballast inductor in the ballast. As bimetallic contacts in the glow bottle become heated, the contacts separate, causing the inductor to transfer energy to the lamp for causing the lamp to ignite. Once ignition occurs, arc current in the lamp increases and the ballast inductor limits the current to the rating of the lamp.
However, the glow bottle has limitations. The lamp may not start on the first pulse, resulting in the bimetallic contacts cooling. The bimetallic contacts then close and cause current to build up in the ballast inductor. The start cycle then repeats, causing an annoying flicker in the lamp. It would be desirable to provide an economical lamp ballast overcoming these limitations.